that is excessive would be very hard to enforce in the UK and IIRC can be worked around in the USA too by moving to a state where they're not enforced - California for example
I've got a 12 month one (UK) - a previous employee from another company in our group left, challenged it in court and won.
It is a faff though if they attempt to enforce it regardless of whether it actually stands up or not....
What he said. Restrictive covenants can be enforced if they are short enough and precise enough, but case law shows that most of the time the employer has written them to be too restrictive and a court would go in your favour.